The present invention concerns, first, a piston-rod scraping ring accommodated in a groove in a dashpot cap and, second, a method of inserting such a ring in such a groove.
Piston-rod scraping rings of elastic materials, especially intended for scraping water and dirt off piston rods, and accommodated in a groove in a dashpot cap are known from German 3 443 370 C2.
There are many ways of securing such piston-rod scraping rings to the upper cap of a dashpot. One way is disclosed in German 3 443 370 C2. The cap is secured by means of a groove that is open radially and, in one direction, axially, by a sleeve that axially and radially encloses the rim around the ring and is forced into a bore in the groove. The compression secures the sleeve and hence the ring. There is a drawback to this approach in that the sleeve necessitates additional material and work.
Another approach to attaching such a cap to a dashpot is known from German Patent 1 140 705. The piston-rod scraping ring is again inserted in a groove that is open radially and, in one direction, axially, and secured there radially by compression at the end of the outer cylinder. One drawback to this approach is that the ring remains loose and can accordingly get lost before it is finally secured in place. Furthermore, to protect it from deformation or eccentricity, the cap must be inserted very precisely in the groove before the dashpot is assembled.
German 19 921 696 A1 discloses a seal accommodated in an inward-opening groove in a cap. The actual sealing mass employed in such seals must be well inserted axially in the groove. Furthermore, the mass must be secured in the nut somehow or radially tensioned, making the groove difficult to machine precisely and necessitating an additional component.
The object of the present invention is accordingly a piston-rod scraping ring and a groove in a dashpot cap improved to the extent that the ring can easily be inserted into the groove and secured there until the overall dashpot is assembled.
The advantages of the present invention are that the ring can be fastened to the cap by simple means and with low expenditure and before the dashpot is finally assembled. Embodiments of the present invention will now be specified with reference to the accompanying drawing, wherein